Motor operated wrench having gear transmission



Jan. 16, 1951 w. R. KAHLE ETAL MOTOR OPERATED WRENCH HAVING GEAR TRANSMISSION Filed Aug. 25, 1948 2 Sheets-Sheet l N S. S. O EA w W/ W D R MM mwQ Y B Jim 1951 w. R. KAHLE ET AL 2,538,251

MOTOR OPERATED WRENCH HAVING GEAR TRANSMISSION Filed Aug. 25, 1948 2 Sheets-Sheet 2 INVENTORS. MLTER R. KAHLE y EDWARD R. dOH/VSON IT 9.; v

y 2 z; 2 Aii s.

Patented Jan. 16,1951

Moroa OPERATED WRENCH HAVING GEAR. TRANSMISSION Walter R. Kahle and Edward R. Johnson, Gincinnati, Ohio, assign-ors to The Morris Machine Tool Company, Cincinnati, Ohio, a corporation of Ohio Application August 25, 1948, Serial No. 46,142

10 G-lai-ms.

wrench head.

A further object of this invention is to provide a power wrench which may be operated by a handle, which l'handle may be swung in one direction for advancing and retracting the. wrench head, and which may he swung in another direction for operating control switches.

A further object of this invention is to provide a power wrench having control mechanism which {automaticaly is stopped as :a nut operated by the wrench reaches the limit of its movement.

A further object of this invention is to provide means in connection with controls of a power wrench, to prevent indexing {of a turret while the wrench head is engaged.

The above and other objects "are attained loy the means described herein and disclosed in the accompanying drawings, in which:

Figure 1 is a .side elevational view showing a power wrench constructed acoordance'with this invention, the wrench being shown in posttime for operating work-piece holders on a machine tool, the wrench being shown partly broken away and in section for clarity of detail. 7

Figure 2 is a sectional view along a line -2 2 in Figure :1, a casingf the power wrench being partly broken away to reveal details of :construction.

Figure 3 is a side elevati'onal view of the lower portion of the :power wrench illustrated in Figure l, the wrench being shown partly broken away and in section along a control shaft.

Figure 4 is a sectional view along a line 4-4 in Figure 3.

Figure 5 is a iragmentary sectional view along a line 5-5 in vFigure 3.

Figure 16 151 8, fragmentary sectional view along 2 turns a worm wheel 15. The worm wheel l6 drives an idle gear I' l which, in turn, drives a splined gear I 8. The splined gear [8 drives a spline'd shaft [9, which extends through the axis or" the splined gear IS. The shaft l9 rotates with, and can slide axially through, the gear IS. A wrench head 21, splined to an end of the shaft is, can be moved into engagement with a. out 2-2 for turning the nut. The spl i ried shaft terms a smooth section 23 of reduced diameter about which a block 24- fits -(see Figure 5) and the shaft is rotatable within the block 24; A pin 26 pro jeots outwardly from the block '24 and meshes with a dog 25 (Figure 4 The dog 21 tum is fixed to a transverse operating or control shaft 28. The block 2t and pin 216 may he moved lengthwise of the axis of thesp lined shaft 19 as the control shaft 28 is turned, and the block- 24 bears against a shoulder 29 on the splined shaft,

for advancing the 'splined shaft and the-wrench head 21 axially towardthe nut 212 (Figure 31), A coil spring Ski serves to retract thelsplined sham and the wrench head.

The dog .27 is mounted at an end of the conitrol shaft 28. At the other end of the shelf-tn is a bifurcated head or clot/ism, which embraces (as shown in Figure 3 l a switch cam The cam '33 is supported by '12. pin 36 that passes through opposite clevis jaws. The cam 33 may rock about the pin 34 randialso may turn with the shaft 28. A handle '36 is attached to the switch cam 33 by ashaft The cam 33 .andiharrdle 3:6 may be swung with the shaft 228 :Eo'r advancing and retracting the wrench Thread .21. l p-addition, the cam and handle can he swung about the pin 36 for operating-a pair of switches 38 and 39, The switches 38 and 138 may actuate appropriate electric circuits (not shown) for driving a the motor it) in forward and reverse directions Thus, the operator of the device not only advance the wrench head 24 into engagement with the out 2-2, but also can start the motor aw in either direction by a swinging movement of the handle 36. A thirdswitch 41 is actuated upon rotationof theshaftlfl. A lug 42 attached tothe, shaft 2-8 may actuate the switch 41 when the wrench head 21 is tuliy retracted.

The nut 22 operates-1a work-holder 4; for clamping a work-piece 44 to a rotatable turret :5. As will 'be understood, the turret it may ibze rotated to advance the'workspiece to a plurality I of work stations, the workpiecereturning 'to its initial position after work on it has beenficomi-" moved; Theswitch' irl "may be connected ccoy an appropriate circuit, not shown) to means for rotating the turret 45. As long as the wrench head 2| and nut 22 are engaged, the means for rotating the turret may be disconnected, so that the turret cannot be rotated while the wrench head 2| and nut 22 are engaged.

The device which has been described in general terms up to this .point will now be described in more detail.

The motor I (Figure 1) may be a torque type electric motor which may stall under high load when the nut 22 is fully advanced. The motor I0 is supported at the upper end of a hollow main casing 41. Bolts 48, only one of which is shown, hold the motor I0 on the casing 41, with the shaft II vertical. The casing 41 is bolted to a housing 49 of a machine tool by bolts 5|. Only a portion of the machine tool is shown, for details of construction of the machine tool do not constitute a feature of the present invention.

A dog tooth clutch member 52, which forms a portion of the lost motion mechanism I 3, is keyed to the motor shaft I I. A set screw holds the clutch member 52 in place on the motor shaft I I. As shown in Figures 1 and- 2, the. clutch member 52 includes two downwardly-extending teeth 53. The worm shaft I2 carries a lower clutch member 54, having upwardly extending teeth 56 which can contact the teeth 53. The lower clutch member 54 is keyed to the shaft I 2. A set screw 51 holds the lower clutch member 54 in place on the shaft I2. When the motor I8 starts, the shaft I I may rotate for a part of a turn before the teeth 53 and 56 come in contact. A hammer blow is struck by the teeth for turning the shaft I2 and for initially starting and loosening the nut 22.

The clutch members 52 and 54 and the worm shaft I2 turn inside and are rotatably mounted in a cavity 58 inside the casing 41. The shaft I2 is journaled in upper and lower bearings indicated at 59 and 6| respectively. The lower bearing 6| is mounted in a well 62, in the lower portion of the casing 41. The upper bearing 59 is held against a shoulder 63 on the shaft I2 by an annular bracket 64. The bracket 64 in turn is bolted to a shoulder 65 inside the casing 41.

The worm I4 is keyed to the shaft I2. A spacer ring 66 holds the worm I4 in spaced relation above the lower bearing 6 I. A shoulder 61 on the shaft I4 holds down the worm I4.

As is shown in Figure 2, the worm I4 meshes with the worm wheel I6. The worm wheel I6 is keyed to a short transverse shaft 68 journaled in appropriate bearings 69 and 10. A spur gear 1| is also keyed to the shaft 68. The worm wheel I6 and spur gear 1| revolve together. The spur gear 1| meshes with the idle gear I1 which, in turn, is mounted on a second short transverse shaft 12 appropriately journaled in bearings 13 and 14. The idle gear I1 further meshes with the splined gear I8. The splined gear is journaled in bearings 15 and 16, which bearings not only support the gear I8, but also support the splined shaft |9 for rotation with and movement axially inside of the splined gear I8. The bearings are mounted in appropriate seats in a plate 11 and a housing member 18 which form opposite sides of a housing about the gears. The plate 11 and housing 18 are attached to the casing 41 by screws 19 (Figure 1). An end plate 80 (Figures 2 and 3) attached to the plate 11 and housing 18 by screws 8|, covers the splined gear I8 and forms an end closure for the housing about the gears.

The splined shaft I9, as shown in Figures 2 and 5, is splined for about one-half its length. The

rest of its length is smooth and of reduced diameter, as shown at 23. The wrench head 2| is splined to the shaft I0 and is held in place on the shaft by a set-screw 82. The head 2| has outwardly-projecting teeth 83, which can mesh with complementary teeth 84 on the nut 22. The inner end of the wrench head 2| may be frustoconical in shape, as indicated at 86. A guideplate 81 surrounds the splined shaft. The frustoconical inner end 86 of the wrench head is receivable in a frusto-conical opening 88 in the guide plate 81. The guide plate 81 is attached to the plate 11 by screws 89, and the inner end of the guideplate 81 holds the bearings 15 in lace. When the wrench head 2| is fully retracted, the inner end 86 of the wrench head can fit in the opening 88.

The housing 18 surrounds the control shaft 28. A cover plate 9| affords access to the hollow interior of the housing 18. A bore 92 through the cover plate 9| rotatably receives the end 23 of the splined shaft I9. A tensioning nut 93 is threaded 0n the end of the shaft I9. The spring 3| is held between washers 94 and 96, which bear respectively on the cover plate 9| and the tensioning nut 93. Tension in the spring 3| can be adjusted by advancing the nut 93 along the shaft. A set screw 91 holds the nut 93 in place on the shaft I9.

As already pointed out, the block 24 receives the smooth section 23 of the splined shaft. The shaft can rotate in a bore 98 through the block 24 (Figure 5). The pin 26 is received in a lengthwise slot 99 (Figure 4) in a side of the dog 21. The dog 21 in turn is fastened to the control shaft 28 by a pin IOI. As shown in Figure 4, the dog 21 can swing to a position shown in full lines from a position shown in dot-dash lines for advancing the pin 26. As already pointed out, movement of the pin 26 advances the block 24, splined shaft I9, and wrench head 2 I, to bring the wrench head into engagement with the nut 22 (Figure 1).

The control shaft 28, as shown in Figure 3, is formed in two sections for ease of assembly. An inner section I02 carries the dog 21, while an outer section I03 carries the clevis 32. The sections are joined by a ribbed joint I86, and the sections rotate together. The control shaft 28 is supported in appropriate bushings I01, I08, and I09. The bushings I08 and I09 are carried in bores in shoulders H2 and H3, that form a part of the housing 18. The outer bushing I01, on the other hand, is supported in a bore in a switch plate H4. The switch plate 4 is attached to the housing 18 by screws I I5, as shown in Figure 1. Referring again to Figure 3, collars I I6 and 1 attached to the sections of the control shaft 28 by set screws, hold the sections of the shaft in place in the housing I8.

The switch 4| is attached to the housing 18 above the shaft 28 by screws I I8. A push-button N9 of the switch 4| extends downwardly from the switch toward the shaft 28. As shown in Figure 6, the lug 42 is threaded in a transverse bore of the shaft 28. An outer end of the lug is rounded and extends outwardly from the shaft 28 into position to contact the'button II9 when the shaft 28 is positioned for retracting the wrench head. When the wrench head is fully retracted, the lug 42 depresses the button I I9.

The switches 38 and 39 are carried by a switch block I2I. The shaft 28 passes through a bore I22 in the switch block. The switch block I2| is attached to the shoulder I|2 by screws 23, as shown in Figure 2, As shown in Figure 3, the

3 switch 38is attached to the upper side or t e switch block, and the'switch'oil is attached x lower side of therswitoh block. yushebutto stems I24 and 426 .of the switches 38 and .39 res spectively, extend toward the switch cam 3,3: 5

The push-buttons 24 and I26 can be depre fied by upper and lower plungers I2! and I28 spectively. vThe ,plungers I2! and H8 can M, pushed inwardly as the switch cam 33- is sw ngabout the p nft ach plun er moves a the switch plate H4. Coil springs 139 Q, 7 I30 abut the stems I24 and I26 and serve tothe plungers resiliently away from the swit 38 and 39 when not depressed by the SW cam 33. v

The switch cam '33 is held normally in a tral position by a flat-headed plunger I31. plunger [-31 can move in a well in the shaf between the jaws of the clevis 32. A coil sp ng 1-32 urges the flat head'of the plunger 43-! aga an inner face I33 of the switch cam 33, to old the cam in the neutral position. As shown in Figures 3 and I. the inner fa 4stof the switch cam is flat x ept f a cutaway portion [34 in a lower corner. As shown in Figure 3, a collar l35 about the clevis 3 2 m s the distance the switch cam can swing a ut th p Wh t handle 36 is. pu hed an wardly to a position shown in'dot-dash linesliu Figure 3., the upper switch .38 is actuated. The an upper switch 38 may control operation of motor during tightening of the nut 22. The lower switch 39, on the other hand, may control opera.- t'ion of the motor during. loosening of them 1t. When the nut is to be loosened, the handle 35 may be pulled outwardly and moves from t a the outer position shown in dot-dash lines. As the handle advances, the plunger I28 follows .-the cam-surface I34, and the switch 39 is disc'onw nected to stop the motor 'I O when the hilt is suiiiciently loosened.

. As shown in Figure 1', the turret carries 'a plurality of, workeho'lders with associated o erate its nuts. The turret may be in the formfio a lar'ge disc with work-holders mounted around the eri heral edge; Each work-holder can ,e1 indexed, in turn, "to each of a series of we I; stations at which macninfingfofthe worklpie may take place. The workholder'na is shown the station at which work pieces are htrod' H into andremoved-from the machine. Tnis'ty c of turret andwork-nclder'is known. .In Figure three of the work holders are shown; all 1; holders being of similar construction, Similar parts of the second and third work holding .device being given the same numbers as parts of the Word holder 43, with the addition olifthe letter" f A after the numeral for parts of the second work-holder, and the letter 'B' after 'the num'eral for parts of the third wc'rk holder. 'Dctails of construction of the work-holders best shown in connection with the second work- 'n'older, which is indicated at 43'-A. The work; holder ta-A is of v-sjnape, having a pair of jaws i3'5-A, which may enga e and hold a idisce shaped work piece MA. A low'erehd I'3'6-.-A of the work-holder 43A is hinged at I 3l..-A to a bracket 38??"13- The bracket I'-"58--.A in turn attached'to the turret 45 by screws I 3'9.A. The no nut 22A is threaded on a stud l4 IeA which extends from the turret toward the powerwrench. When the nut is turned, it advanced in or out along the stud to clamp or unclampthe work piece.

The operation of the power wrench will be clear from the foregoing detailed description and from the drawings. The work piece 44 may be placed under the jaws I35 when the nut 2-2 A is in released position. Then the operator of the device may swing the handle 36 toward the work piece, as shown in Figure l, to bring the wrench,- head 2| into engagement with the nut 22. When the wrench head 2| and nut 22 are engaged, the handle 35 can be pushed inwardly toward the wrench, as indicated in Figure 3, to depress the plunger I21 and actuate the switch 33, starting Figure 1 to engage the wrench head 2! and nut 22. The handle is pulled outwardly as shown in Figure 3 to actuate the switch 39. As the nut 22 rides along the stud Idl, the handle 36 moves to; the ght, as shown in Figure 1. The plunger I28 follows the cam-surface I34 of the switch cam :33. releasing the switch 39 and halting the motor when the nut is released. Then the fill-r ishecl worle piece may be removed and a new Wo k p ce substituted. I

Power is transmitted from the motor it through the lost-motion device I3 the worm I4 and gears It, M, ii, and I8, to the splined shaft It. The shaft IS can be advanced axially through the center of the gear I8 when the handle 35 is swung toward or away from the turr'at '45, as shown in Figure 1. As the handle 35 and control shaft 28 are swung to the left (Fig.- ures 1 and 2,) the dog 2'? drives the block 24 against the shoulder 28 for advancing the wrench head 2I. When the handle 35 is released, the spring 3| retracts the wrench head EI and Shaft l9.

The lost-motion device It gives a hammer blow at the start of the release of the nut for in iti'ally freeing the nut. The switch 4! prevents premature indexing of the turret is'while the wrench head-and nut are engaged. If desired, the motor can be put in operation in either direc: tion before the nut and wrench head are fully engaged; to bring the teeth 83 of the wrench head into alignment with the teeth 84 of the nut.

As will be understood, the element-to-bee turned may take various forms and need not he a nut. Many variations of the device are possible; and the invention is not intended to be limited by the foregoing detailed description and the drawings. except asset out in the appended claims.

What-is claimed is: v

1.- In a control device for a power wrench hav ing .a rotatable and axially advanceable shaft, a head attached to the shaft for engaging an ole.- ment-tmbe-turned, and means for rotating the shaft, the combination of a control shaft ally rotatable through an acute angle arc, linking the first mentioned shaft with the COilc-I. trol shaft for advancing the first mentioned shaft to bring the head intoengagement with the ele ment-to-be-turned upon partial rotation of said control shaft, a switch cam mounted on said contml shaft to rotate with said control shaft and to about an-axis at a rightiangle to said control shaft, a pair of switches selectively opera able said switch cam upon swinging "said? switch cam in opposite directions, and means connected to said switch cam for swinging said switch cam and for imparting partial rotation to said control shaft.

2. In a control device for a power wrench having a rotatable and axially advanceable shaft, a head attached to the shaft for engaging an element-to-be-turned, and means for'rotating the shaft, the combination of a control shaft manually rotatable through an acute angle arc, means linking the first-mentioned shaft with the control shaft for advancing the first mentioned shaft to bring the head into engagement with the element-to-be-turned upon partial rotation of said control shaft, a switch cam mounted on said control shaft to rotate with said'control shaft and to swing about an axis at a right angle to said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, a third switch operable by said control shaft upon partial rotation of said control shaft, and means con nected to said switch cam for swinging said switch cam and for imparting partial rotation to said control shaft.

3. In a control device for a power wrench having a rotatable and axially advanceable shaft, a head attached to the shaft for engaging an element-to-be-turned, and means for rotating the shaft, the combination of a control shaft m anu ally rotatable through an acute angle arc, means linking the first mentioned shaft with the control shaft for advancing the first mentioned shaft to bring the head into engagement with the element-to-be-turned upon partial rotation of said control shaft, a switch cam mounted on said control shaft to rotate with said control shaft and to swing about an axis at a right angle to said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, means connected to said switch cam for swinging said switch cam and for partially rotating said control shaft, and resilient means for retracting said head and said axially advanceable shaft upon release of said cam-operating means.

4. In a control device for a power wrench having a rotatable and axially advanceable shaft, a

head attached to the shaft for engaging an ele- 'ment-to-beturned, and means for rotating the shaft, the combination of a control shaft manually rotatable through an acute angle arc, means linking the first mentioned shaft with'the control shaft for advancing the first mentioned shaft to bring the head into engagement with the element-to be-turned upon partial rotation of said control shaft, a switch cam mounted" on said control shaft to rotate with said control shaft andto swing about an axis at a right angle to said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, a third operable by said control shaft upon partial rotation of said control shaft, means connected to said switch cam for swinging said switch cam and for imparting partial rotation to said control shaft, and resilient means for retracting said head and said axially advanceable shaft upon release of said cam operating means, said third switch being actuated when the head is in retracted position.

5. In a control device for a power wrench having a rotatable and axially advanceable shaft, a head attached to the shaft for engaging an element-to-be-turned, and an electric motor for rotating the shaft, the combination of a control shaft manually rotatable through an acute angle arc, means linking the axially advanceable shaft with the control shaft for advancing the first mentioned shaft to bring the head into engagement with the element-to-be-turned upon partial rotation of said control shaft, a switch cam mounted on said control shaft to rotate with said control shaft and to swing about an axis at a right angle to said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, a housing about said control shaft, said switches being attached to said housing, one of said switches actuating the motor during tightening of the element, the second of said switches actuating the motor during loosening of the element, means for releasing the second of said switches when the element is loosened a predetermined amount, and means connected to said switch cam for swinging said switch cam and for imparting partial rotation to said control shaft.

6. In a power wrench, the combination of a rotatable and axially advanceable shaft, means for rotating the shaft, a head attached to the shaft for engaging an element-to-be-turned, a control shaft manually rotatable through an acute angle arc, means linking said control shaft to said first mentioned shaft for axially advancing said first mentioned shaft upon partial rotation of said control shaft, a switch cam mounted on said control shaft to rotate with said control shaft and to swing about an axis at a right angle to said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, and means connected to said switch cam for swinging said switch cam and for imparting partial rotation to said control shaft.

'7. In a power wrench, the combination of a rotatable and axially advanceable shaft, means for rotating the shaft, a head attached to the shaft for engaging an element-to-be-turned, a control shaft mounted at a right angle to said first mentioned shaft and manually rotatable through an acute angle arc, a dog extending outwardly from said control shaft and linked to said first mentioned shaft for axially advancing said first mentioned shaft upon partial rotation of said control shaft, a switch cam mounted on said control shaft to rotate with said control shaft and to swing about an axis at a right angle to said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, and means connected to said switch cam for swinging said switch cam and for imparting partial rotation to saidcontrol shaft.

"8. In a power wrench, the combination of a rotatable and axially advanceable shaft, an electric motor for rotating the shaft, a head attached to the shaft for engaging an element-to-beturned, a control shaft mounted at a right angle to said first mentioned shaft and manually rotatable through an acute angle arc, a dog extending outwardly from said control shaft and linked to said first mentioned shaft for axially advancing said first mentioned shaft upon partial rotation of said control shaft, a switch cam mounted on said control shaft to rotate with said control shaft and to swing about an axis at a right angle to'said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, a housing about said control shaft, said switches being attached to said housing, one of said switches actuating the motor during tightening of the element, the second of said switches actuating the motor during loosening of the element, means for releasing the second of said switches When the element is loosened a predetermined amount, and means connected to said switch cam for swinging said switch cam and for imparting partial rotation to said control shaft. 3 V

9. In a power wrench for a machine having an element-to-be-turned positionable for turning by the wrench, the combination of a rotatable and axially advanceable shaft, means for rotating the shaft, a head attached to the shaft for engaging the element-to-be-turned, a control shaft mounted at a right angle to said first mentioned shaft and manually rotatable through an acute angle are, a dog extending outwardly from said control shaft and linked to said first mentioned shaft for axially advancing said first mentioned shaft upon partial rotation of said control shaft, a switch cam mounted on said control shaft to rotate with said control shaft and to swing about an axis at a right angle to said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, a third switch operable by said control shaft upon partial rotation of said control shaft, said first two switches actuating the shaft-rotating means in opposite directions for tightening and loosening the element, means controlled by the third switch for preventing movement of said element out of position for engagement by the head while engaged thereby, and means connected to said switch cam for swinging said switch cam and for imparting partial rotation to said control shaft.

10. In a control device for a power wrench having a rotatably and axially advanceable shaft, a head attached to the shaft for engaging an element-to-be-turnedland means for rotating the shaft, the combination of a control shaft manually oscillatable through an angle of less than a half turn, means linking the first mentioned shaft with the control shaft for advancing the first mentioned shaft to bring the head into engagement with the element-to-be-turned upon oscillation of said control shaft in one direction, a switch cam mounted on said control shaft to oscillate with said control shaft and to swing upon an axis at a right angle to said control shaft, a pair of switches selectively operable by said switch cam upon swinging of said switch cam in opposite directions, and means connected to said switch cam for swinging said switch cam and for oscillating said control shaft.

' WALTER R. KAHLE.

EDWARD R. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,479,178 Harvey Jan. 1, 1924 1,823,426 Ferris Sept. 15, 1931 2,140,223 Foster Dec. 13, 1938 2,180,488 Van Hamersveld Nov. 21, 1939 2,433,959 Runkle Jan. 6, 1948 FOREIGN PATENTS Number Country Date 867,335 France July 21, 1941 

